US 12,487,306 B2
System and method for variable-flip-angle 3D spiral-in-out TSE/space using echo-reordering and concomitant gradient compensation
Zhixing Wang, Charlottesville, VA (US); Rajiv Ramasawmy, Bethesda, MD (US); Ahsan Javed, Vienna, VA (US); John P. Mugler, III, Charlottesville, VA (US); Craig H. Meyer, Charlottesville, VA (US); and Adrienne E. Campbell, Washington, DC (US)
Assigned to University of Virginia Patent Foundation, Charlottesville, VA (US); and The United States of America, as represented by the Secretary, Department of Health and Human Services, Washington, DC (US)
Filed by University of Virginia Patent Foundation, Charlottesville, VA (US)
Filed on Jan. 2, 2024, as Appl. No. 18/402,593.
Claims priority of provisional application 63/436,679, filed on Jan. 2, 2023.
Prior Publication US 2024/0272258 A1, Aug. 15, 2024
Int. Cl. G01R 33/58 (2006.01); G01R 33/561 (2006.01)
CPC G01R 33/5615 (2013.01) [G01R 33/586 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A computer implemented method of gathering three-dimensional (3D) magnetic resonance imaging (MRI) data using spiral-in-out encoding trajectories from a k-space encoding orientation and a spoiler gradient direction, the method comprising:
using a computer having a processor and computer memory to implement steps comprising:
calculating a variable flip angle radio frequency (RF) series for use as refocusing pulses, wherein the RF series comprises a plurality of refocusing RF pulses;
applying a spoiler gradient waveform along the spoiler gradient direction, wherein the computer alternately adds and subtracts partition encoding waveforms to the spoiler gradient waveform;
reading MRI data with the computer for each encoding step associated with the k-space encoding orientation during an MRI sequence further comprising:
inserting a spiral-in gradient before a first refocusing RF pulse from the RF sequence;
overlapping a prewinder lobe for the encoding trajectory with the spoiler gradient waveform having the partition encoding waveforms added therein; and
overlapping a rewinder lobe for the encoding trajectory with the spoiler gradient waveform having the partition encoding waveforms subtracted there from.